This is interesting. I just had a similar problem, but in reverse.
I changed the shell and once putting back together the SLite I made a hole in the fan ribon cable. So, fan dead.
Anyhow, I tried to switch on the Lite -with no fan connected- and oh suprise, dead screen, but I still could hear the clikly sound in the menu, but no image. So there was still hope.
So I ordered a new screen and a new fan. After replacing the fan only, the screen went back alive.
So my theory is that the system unstress the system cuting the image when the fan is disconnected or dead. In order to avoid killing the cpu and all the rest.